At the annual meeting of the Polish American Congress Sept. 28, Republican presidential nominee Donald Trump spoke about his criticism of NATO and seemed to imply it led to changes in policy. (The Washington Post)

Republican presidential nominee Donald Trump vowed to strengthen the North Atlantic Treaty Organization during a campaign event Wednesday in Chicago, though he has been critical of the amount of money the United States has spent on the alliance in the past.

"We'll work with Poland on strengthening NATO. When I am president, we will strengthen NATO," Trump said during a speech at the Polish National Alliance in Chicago.

Trump praised Poland for being just one of five NATO countries meeting its defense spending target, 2 percent of GDP under official NATO guidelines, and criticized other countries for being "delinquent." Trump said he wants NATO to be stronger and that other countries should also meet their spending targets.

Seeking to counteract criticism for his suggestion earlier this year that NATO was “obsolete,” Trump characterized his statement at the time as focusing on the alliance’s counterterrorism efforts. Trump claimed credit for recent changes to NATO’s terrorism efforts; fact checkers and experts have discredited that assertion.

Trump's early critiques of NATO rested on the cost to the United States — not on NATO's counterterrorism operations. During an interview with The Washington Post’s editorial board in March, he bemoaned that other countries were not spending more despite escalations in Ukraine having more effect on Europe than on the United States.

"And I think the concept of NATO is good, but I do think the United States has to have some help. We are not helped. ... When you look at the kind of money that our country is losing, we can’t afford to do this. Certainly we can’t afford to do it anymore,” he told The Post in March.

Former New York City mayor Rudolph W. Giuliani introduced Trump on Wednesday, saying that Trump will be "a totally reliable ally" to Poland. Giuliani blasted the Obama administration for the attempt to reset relations with Russia while Democratic presidential nominee Hillary Clinton was secretary of state. He said the Russian reset compromised the security of Poland and the Czech Republic, and he accused Obama and Clinton of “double-crossing” the two countries.

Giuliani also stressed Trump’s commitment to NATO.

“If you elect Donald Trump, you will find a man who understands that Poland, unlike some of the countries he’s pushing a little for a little more money, Poland pays its bills to NATO,” Giuliani said. “So he’ll defend the NATO treaty. It’s a solemn obligation of the United States. Yes, he’s going to push some of the people that aren’t paying their fair share to pay more. But that doesn’t mean he doesn’t understand his solemn obligation.”

Giuliani called Russian President Vladimir Putin a "bully" and defended Trump against charges that he is too cozy with Putin, who he has praised in the past.

"He doesn’t know Putin. He's never met Putin. Will he negotiate with Putin? Yes. Did Reagan negotiate with Gorbachev? Yes," Giuliani said. "But he's going to negotiate with him from a position of military strength that dwarfs the Soviet U— I'm sorry, Russia."